Rotary engine driven lawn mowers have been in existence for many years. Typically, there is an engine driven spindle with a mower blade interconnected to the lower end thereof. The spindles may be used singularly or in multiples, directly driven or indirectly driven as by a belt. Historically, the mower blade is interconnected to the bottom of the spindle by a removable bolt, thus allowing the blade to be removable and replaceable upon selective manipulation of the bolt. Due to the necessity of passing increased torque between the spindle and the blade, and especially due to the need to pass bidirectional torque due to blade brakes and otherwise, there is now more and more frequency a complex interconnection between the blade and the spindle. This has caused manufacturers to provide for some sort of radial solid interconnection between the spindle and the blade in order to pass this torque. Examples of this are shown in the Myszka U.S. Pat. No. 5,454,216 and the Sheldon U.S. Pat. No. 5,284,006. These interconnections are functional in increasing the torque which is capable of being transferred to and from the spindle and the blade. The interconnections are, however, occasionally inconvenient to make due to the necessity of radially and laterally aligning the toothed opening in the blade with the corresponding shape in the spindle to mount the blade on the spindle.